Monitoring air quality with a $12 sensor

[Chris] has allergies, asthma, and uses a wood burning stove. You can imagine why testing his air quality might be something he’d be interested in. He has a very nice $290 laser particle counter, but was really curious how the $12 sharp sensor he found would stack up. To find out, he plugged it into an arduino and started logging both on pachube.

After a few different tests, like lighting a match, blowing it out, and letting the smoke flow into the sensors, he decided he needed something better. Cooking some pancakes turned out to be his ultimate method. After charting the dissipation of particles after cooking a nice batch of griddle cakes, he found the two sensors to be surprisingly similar.

It turns out that the air quality in the average home is absolutely terrible, more so for city living. We’ve tested a few of these sensors and found the sensitivity to be very poor (they only work particularly well in the case of high particulate concentrations) so we’ve focused more on laser-based particle detection. On average, you’ll see proportionally higher concentrations of particles at 2.5 micron and below, which this sensor does not do well with.

Still, it’s very promising to see others taking an active interest in air quality. Nicely done!

I got the $15.50 Shinyei Dust sensor (http://www.seeedstudio.com/depot/
grove-dust-sensor-p-1050.html) hooked up to the Arduino last night
and got it posting to Pachube (https://pachube.com/feeds/56469)
The interface is digital and pretty simple (you calculate the ratio of
how long the I/O pulses are low compared to high over 30 seconds).

The Shinyei looks much more promising for cheap processors like the
Arduino. I didn’t have to deal with the quality of the A/D converter
or additional circuitry. Time will tell, but it looks like I have more
correlation at lower particle concentrations.

Where might we find an affordable and portable outdoor air quality detector as prepare to explore NM and AZ for retirement sites next spring? My wife has breathing problems in the unhealthy Fresno, CA environment. Thank you very much!